SPDIF on Windows
Lots of problems have been reported on windows. Often this is accompanied by "audio output is late/starving" errors.
One user says: VLC doesn't change the samplerate and tries to output 48khz while the device is still in 44.1khz. This can indeed be the problem, since VLCs SPDIF resampler is a dummy resampler, that cannot handle resampling properly. (The OSX audio output recently ran into the same issue)